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A nova super-remnant (NSR) is an immense structure associated with a nova that forms when frequent and recurrent nova (RN) eruptions sweep up surrounding interstellar medium (ISM) into a high-density and distant shell. The prototypical NSR, measuring over 100 pc across, was discovered in 2014 around the annually erupting nova M 31N 2008-12a. Hydrodynamical simulations demonstrated that the creation of a dynamic NSR by repeated eruptions transporting large quantities of ISM is not only feasible but that these structures should exist around all novae, whether the white dwarf (WD) is increasing or decreasing in mass. But it is only the RN with the highest WD masses and accretion rates that should host observable NSRs. KT Eridani is, potentially, the eleventh RNe recorded in the Galaxy and is also surrounded by a recently unveiled H α shell tens of parsecs across, consistent with an NSR. Through modelling the nova ejecta from KT Eri, we demonstrate that such an observable NSR could form in approximately 50 000 yr, which fits with the proper motion history of the nova. We compute the expected H α emission from the KT Eri NSR and predict that the structure might be accessible to wide-field X-ray facilities.
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Introducing the Condor Array Telescope – IV. A possible nova super-remnant surrounding the putative recurrent nova KT Eridani
Just 10 recurrent novae (RNe) – which erupt repeatedly on time-scales shorter than one century – are known in our Galaxy. The most extreme RN known (located in the Andromeda galaxy), M31N 2008-12a, undergoes a nova eruption every year, and is surrounded by a vast nova ‘super-remnant’, 134 pc in extent. Simulations predict that all RNe should be surrounded by similar vast shells, but previous searches have failed to detect them. KT Eri has recently been suggested to be a RN, and we have used the Condor Array Telescope to image its environs through multiple narrow-band filters. We report the existence of a large (∼50-pc diameter), H $$\, \alpha$$-bright shell centred on KT Eri, exactly as predicted. This strongly supports the claim that KT Eri is the 11th Galactic recurrent nova, and only the second nova known to be surrounded by a super-remnant. SALT spectra of the super-remnant demonstrate that its velocity width is consistent with that of M31-2008-12a.
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- PAR ID:
- 10538939
- Publisher / Repository:
- MNRAS
- Date Published:
- Journal Name:
- Monthly Notices of the Royal Astronomical Society
- Volume:
- 529
- Issue:
- 1
- ISSN:
- 0035-8711
- Page Range / eLocation ID:
- 224 to 235
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1093/mnras/stad3612
